Polymers with a comb structure of pendant side chains are a new class of organic materials which exhibit interesting optical properties.
In U.S. Pat. Nos. 4,694,066; 4,755,574; and 4,762,912 liquid crystalline polymers are described which have pendant side chains which exhibit nonlinear optical susceptibility, in addition to mesogenic properties.
U.S. Pat. No. 4,792,208 discloses nonlinear optically responsive organic compounds and side chain polymers in which the molecular dipoles have an electron donor moiety linked through a conjugated .pi. bonding system to an electron acceptor sulfonyl moiety.
U.S. Pat. Nos. 4,808,332 and 4,810,338 disclose polymers with pendant side chains in which a stilbene-type structure or a diphenylbutadiene-type structure is in conjugation with an electron-donating group and an electron-withdrawing group. These extended conjugated dipolar electronic systems exhibit an exceptionally high level of second order nonlinear optical susceptibility .beta..
Thin films of organic or polymeric materials with large second order nonlinearities in combination with silicon-based electronic circuitry have potential as systems for laser modulation and deflection, information control in optical circuitry, and the like.
Of specific interest with respect to the present invention are publications such as U.S. Pat. Nos. 3,678,082 and 4,540,743 which describe the esterification of alcohols in the presence of an aminopyridine catalyst.
Because of the important applications of nonlinear optically responsive organic compounds and polymerizable monomers, there is increasing research effort to develop new and improved methods for synthesizing the conjugated dipolar electronic structures which provide the desirable optical properties.
Accordingly, it is an object of this invention to provide a novel method for the synthesis of organic compounds and polymerizable monomers which exhibit a high level of nonlinear optical response.
It is a further object of this invention to provide an improved multistep process for the production of acrylate monomers having a chemical structure characterized by an electron-donating group which is linked through a conjugated electronic system to an electron-withdrawing group.
Other objects and advantages of the present invention shall become apparent from the accompanying description and examples.